scholarly journals Effects of different biomass materials as a salt-isolation layer on water and salt migration in coastal saline soil

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11766
Author(s):  
Mao Yang ◽  
Runya Yang ◽  
Yanni Li ◽  
Yinghua Pan ◽  
Junna Sun ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Salt Concentration ◽  
Saline Soil ◽  
Soil Depth ◽  
Soil Layer ◽  
Thick Layer ◽  
Peat Layer ◽  
Salt Accumulation

The aim of this study was to find a material suited for the prevention of evaporative water loss and salt accumulation in coastal saline soils. One-dimensional vertical water infiltration and phreatic evaporation experiments were conducted using a silty loam saline soil. A 3-cm-thick layer of corn straw, biochar, and peat was buried at the soil depth of 20 cm, and a 6-cm-thick layer of peat was also buried at the same soil depth for comparison. The presence of the biochar layer increased the upper soil water content, but its ability to inhibit salt accumulation was poor, leading to a high salt concentration in the surface soil. The 3-cm-thick straw and 6-cm-thick peat layers were most effective to inhibit salt accumulation, which reduced the upper soil salt concentration by 96% and 93%, respectively. However, the straw layer strongly inhibited phreatic evaporation and resulted in low water content in the upper soil layer. Compared with the straw layer, the peat layer increased the upper soil water content. Thus, burying a 6-cm-thick peat layer in the coastal saline soil is the optimal strategy to retain water in the upper soil layer and intercept salt in the deeper soil layer.

scholarly journals Simulation soil water-salt dynamics in saline wasteland of Yongji Irrigation area in Hetao Irrigation district of China

2020 ◽  
Author(s):  
Chengfu Yuan
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Salt Concentration ◽  
Field Experiments ◽  
Soil Layer ◽  
Irrigation District ◽  
Soil Salt ◽  
Water Salt ◽  
Hetao Irrigation District

Abstract In order to explore the regional water-salt balance mechanism in Hetao Irrigation District. Field experiments were conducted in 2018 and 2019 in Heji canal study area. The SWAP model was calibrated and validated based on field experiments observed data. The SWAP model was used to simulate soil water-salt dynamic in saline wasteland after calibration and validation. The results showed that model simulation results of soil water content and soil salt concentration agreed well with the measured values. Soil water content and soil salt concentration changed obviously under the effect of farmland irrigation in crop growing period. Soil salt was accumulated in saline wasteland. The soil salt accumulation of each soil layer in saline wasteland was 0.164, 0.092, −0.890 and −1.261 mg/cm3, respectively. Soil water content gradually increased and soil salt concentration gradually decreased in autumn irrigation period. Soil salt was leached in saline wasteland. The soil salt accumulation of each soil layer in saline wasteland was −1.011, −1.242, −1.218 and −1.335 mg/cm3, respectively. The saline wasteland became in drainage and salt drainage region for cultivated land. The saline wastelands had an obvious role in adjusting salt balance and maintain salt dynamic balance in Hetao Irrigation District.

Effects of surface straw mulching and buried straw layer on soil water content and salinity dynamics in saline soils

2020 ◽  
Vol 100 (1) ◽  
pp. 58-68
Author(s):  
Xiliang Song ◽  
Ruojun Sun ◽  
Weifeng Chen ◽  
Manhua Wang
Keyword(s):  
Water Content ◽  
Wheat Straw ◽  
Soil Water ◽  
Soil Water Content ◽  
Field Experiments ◽  
Soil Depth ◽  
Salt Accumulation ◽  
Sodic Soils ◽  
Straw Mulching ◽  
Straw Return

Field experiments were conducted to evaluate the effects of wheat straw return methods, which included the use of surface straw mulch and a buried straw layer, on soil water content, electrical conductivity (EC), and sodium adsorption ratio (SAR) of saline sodic soils in an effort to identify useful ways for reducing soil salt accumulation and enhancing soil water content. The results showed that the straw return treatments were effective for inhibiting salt accumulation and soil water loss, resulting in a reduction of EC and SAR but an enhancement of soil water content. After a year-long experiment, compared with the treatment with no straw return, the straw burial and straw mulching treatments decreased the EC by 10.5% and 3.5%, reduced the SAR by 7.4% and 21.5%, and increased the soil water by 0.9% and 4.4%, respectively. Furthermore, the combined application of straw layer burial and surface straw return had a more significant effect than the individual treatments; the positive effect of straw return occurred mainly focused in the topsoil (0–40 cm) and decreased with increasing soil depth. Our results allowed us to conclude that burial of the straw layer was necessary to enhance the effects of surface mulch, and the combination of surface mulch (3.0 t ha−1 of wheat straw) and straw layer burial (6.0 t ha−1 of wheat straw) proved to be a better straw return method than the others.

Changes in soil water content under annual, perennial, and shrub-based pastures in an intermittently dry, summer-rainfall environment

2010 ◽  
Vol 61 (4) ◽  
pp. 331 ◽  
Author(s):  
G. M. Lodge ◽  
M. A. Brennan ◽  
S. Harden ◽  
S. P. Boschma
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Perennial Ryegrass ◽  
Soil Depth ◽  
Soil Layer ◽  
Summer Rainfall ◽  
Late Winter ◽  
Herbaceous Plant ◽  
Annual Grass

Soil water content (SWC) was monitored in an intermittently dry environment in 2003–08, for the following pasture types: perennial ryegrass (Lolium perenne cv. Skippy), lucerne (Medicago sativa cv. Venus), phalaris (Phalaris aquatica cv. Atlas PG), a lucerne/phalaris mixture, digit grass (Digitaria eriantha ssp. eriantha cv. Premier), and old man saltbush (Atriplex nummalaria). Perennial ryegrass and phalaris pastures persisted until late winter–early spring 2005 and, after that time, were maintained as degraded annual grass pastures and bare fallows, respectively. For all pasture types, mean SWC was generally higher for the 0–0.9 m soil depth than the 0.9–2.1 m (63 v. 51 mm of water per 0.2 m soil layer). At a soil depth of 0–0.9 m, few significant differences in SWC occurred among pasture types. However, significant differences among pasture types were recorded in SWC at depths of 0.9–2.1 m for these perennial-based pastures with low herbaceous plant densities. At this depth the SWC of lucerne/phalaris was lower (P < 0.05) than that of perennial ryegrass and phalaris pasture types in March 2005 (Day 500), and that of the degraded annual grass pasture in August 2006 (Day 1000) and December 2007 (Day 1500). Overall, maximum extractable water was highest (P < 0.05) for digit grass and old man saltbush pasture types (~180 mm) and lowest for the bare fallow (99 mm). Estimates of root depth were highest (2.0 m) for the lucerne/phalaris pasture type.

scholarly journals SURFACE RESIDUES: EFFECTS ON SOIL MOISTURE AND TEMPERATURE1

2021 ◽  
Vol 34 (4) ◽  
pp. 887-894
Author(s):  
GUSTAVO HADDAD SOUZA VIEIRA ◽  
ARILDO SEBASTIÃO SILVA ◽  
ARUN DILIPKUMAR JANI ◽  
LUSINERIO PREZOTTI ◽  
PAOLA ALFONSA VIEIRA LO MONACO
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Block Design ◽  
Soil Disturbance ◽  
Dry Season ◽  
Depth Range ◽  
Sunn Hemp

ABSTRACT This study aimed to determine how crop residue placement and composition would affect soil water content and temperature during the dry season in the central region of Espírito Santo state, Brazil. A 19-week field study was conducted from April to August 2017. A 2 x 4 factorial study with four replications was implemented using a randomized complete block design. Factors were soil management [conventional tillage (CT) and no soil disturbance (ND)] and residue amendment [maize (Zea mays L.), sunn hemp (Crotalaria juncea L.), a maize-sunn hemp mixture, and a no amendment control]. Soil water content and temperature were measured weekly at predetermined soil depth intervals. Soil water content was higher in ND plots amended with surface residues than under all other treatments in the 0 to 0.05 m depth range. All residue amendments in this range were equally effective in conserving soil water. Surface residues reduced soil temperature by up to 8.4 °C relative to the control in ND plots. Incorporating residue amendments by CT cancelled all temperature-moderating benefits provided by surface residues. These results indicate that surface residues from cereals, legumes, or cereal/legume mixtures are equally effective in conserving soil water and moderating soil temperature during the dry season. Additional research is needed to determine how improved soil environmental conditions, generated by surface residues, would affect nutrient acquisition and crop performance.

scholarly journals The spatial variability of soil water content in a potato field before and after spray irrigation in arid northwestern China

2020 ◽  
Vol 20 (3) ◽  
pp. 860-870 ◽  
Author(s):  
Tao Li ◽  
Jian-feng Zhang ◽  
Si-yuan Xiong ◽  
Rui-xi Zhang
Keyword(s):  
Spatial Variability ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Precision Agriculture ◽  
Field Experiments ◽  
Soil Layer ◽  
Northwestern China ◽  
Potato Field ◽  
Arid Northwestern China

Abstract Assessing the spatial variability of soil water content is important for precision agriculture. To measure the spatial variability of the soil water content and to determine the optimal number of sampling sites for predicting the mean soil water content at different stages of the irrigation cycle, field experiments were carried out in a potato field in northwestern China. The soil water content was measured in 2016 and 2017 at depths of 0–20 and 20–40 cm at 116 georeferenced locations. The average coefficient of variation of the soil water content was 20.79% before irrigation and was 16.44% after irrigation at a depth of 0–20 cm. The spatial structure of the soil water content at a depth of 20–40 cm was similar throughout the irrigation cycle, but at a depth of 0–20 cm a relatively greater portion of the variation in the soil water content was spatially structured before irrigation than after irrigation. The autocorrelation of soil water contents was influenced by irrigation only in the surface soil layer. To accurately predict mean soil moisture content, 40 and 20 random sampling sites should be chosen with errors of 5% and 10%, respectively.

scholarly journals Relationship between Very Fine Root Distribution and Soil Water Content in Pre- and Post-Harvest Areas of Two Coniferous Tree Species

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1227
Author(s):  
Moein Farahnak ◽  
Keiji Mitsuyasu ◽  
Takuo Hishi ◽  
Ayumi Katayama ◽  
Masaaki Chiwa ◽  
...  
Keyword(s):  
Water Content ◽  
Root System ◽  
Soil Water ◽  
Soil Water Content ◽  
Tree Species ◽  
Fine Roots ◽  
Fine Root ◽  
Soil Depth ◽  
Tree Cutting ◽  
Coniferous Tree Species

Tree root system development alters forest soil properties, and differences in root diameter frequency and root length per soil volume reflect differences in root system function. In this study, the relationship between vertical distribution of very fine root and soil water content was investigated in intact tree and cut tree areas. The vertical distribution of root density with different diameter classes (very fine <0.5 mm and fine 0.5–2.0 mm) and soil water content were examined along a slope with two coniferous tree species, Cryptomeria japonica (L.f.) D. Don and Chamaecyparis obtusa (Siebold et Zucc.) Endl. The root biomass and length density of very fine roots at soil depth of 0–5 cm were higher in the Ch. obtusa intact tree plot than in the Cr. japonica intact plot. Tree cutting caused a reduction in the biomass and length of very fine roots at 0–5 cm soil depth, and an increment in soil water content at 5–30 cm soil depth of the Ch. obtusa cut tree plot one year after cutting. However, very fine root density of the Cr. japonica intact tree plot was quite low and the soil water content in post-harvest areas did not change. The increase in soil water content at 5–30 cm soil depth of the Ch. obtusa cut tree plot could be caused by the decrease in very fine roots at 0–5 cm soil depth. These results suggest that the distribution of soil water content was changed after tree cutting of Ch. obtusa by the channels generated by the decay of very fine roots. It was also shown that differences in root system characteristics among different tree species affect soil water properties after cutting.

Effects of Typical Chemical Agents on Preventing Pollution and Controlling Drought in a Cherry Orchard

2012 ◽  
Vol 550-553 ◽  
pp. 1340-1344
Author(s):  
Ren Kuan Liao ◽  
Pei Ling Yang ◽  
Shu Mei Ren ◽  
Hang Yi ◽  
Long Wang ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
North China Plain ◽  
North China ◽  
Root Zone ◽  
Soil Layer ◽  
The North ◽  
The North China Plain ◽  
Chemical Agents

In the North China plain, serious Non-point-source (NPS) pollution and drought are two great concerns in agricultural production. In our studies, two typical chemical agents ( SAP and FA ) were selected to control drought and pollution in a cheery orchard. Soil water content, nutrient transport in soil profile have been researched. The results showed that the soil water content of treatments with chemical agents increased maximally by 19.4% relative to treatment without chemical agents, and increased by 35.2% for Ammonium-N in 20-60 cm soil layer ( main root zone ). However, in 60-120 cm deeper soil layer, the water leakage of treatments with chemical agents decreased averagely by 15.1% relative to treatment without chemical agents, and increased by 43.8% for Nitrate-N. The chemical agents hold water and nutrient in root zone and thus reducing the risk of pollutant leaching into the underground water. It can be found that treatment ( 150kg/h㎡ SAP + 300 times FA ) is the optimal combination group in all treatments. The chemical prevention technology provided a new guide for controlling drought and reducing NPS pollution in cherry planting in the North China plain.

An assessment of soil moisture in the MARINE flash flood model using in situ measurements, reanalysis and satellite derived estimates

2020 ◽  
Author(s):  
Judith Eeckman ◽  
Hélène Roux ◽  
Bertrand Bonan ◽  
Clément Albergel ◽  
Audrey Douniot
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Model Calibration ◽  
Flash Flood ◽  
Soil Column ◽  
Subsurface Flow ◽  
Soil Layer ◽  
Observation Network

&lt;p&gt;The representation of soil moisture is a key factor for the simulation of flash flood in the Mediterranean region. The MARINE hydrological model is a distributed model dedicaded to flash flood simulation. Recent developments of the MARINE model lead to an improvement of the subsurface flow representation : on the one hand, the transfers through the subsurface take place in a homogeneous soil column based on the volumic soil water content instead of the water height. On the other hand, the soil column is divided into two layers, which represent respectively the upper soil layer and the deep weathered rocks. The aim of this work is to assess the performances of these new representations of the subsurface flow with respect to the soil saturation dynamics during flash flood events. The performances of the model are estimated with respect to three soil moisture products: i) the gridded soil moisture product provided by the LDAS-Monde assimilation chain. LDAS-Monde is based on the ISBA-a-gs land surface model and integrates high resolution spatial remote sensing data from the Copernicus Global Land Service for vegetation through data assimilation; ii) the upper soil moisture measurements taken from the SMOSMANIA observation network&amp;#160;; iii) The satellite derived surface soil moisture data from Sentinel1. The case study is led over two french mediterranean catchments impacted by flash flood events over the 2017-2019 period and where one SMOSMANIA station is available. Additionnal tests for the initialisation of MARINE water content for the two soil layers are assessed. Results show first that the dynamic of the soil moisture both provided by LDAS-Monde and simulated for the upper soil layer in MARINE are locally consistent with the SMOSMANIA observations. Secondly, the use of soil water content instead of water height to describe lateral flows in MARINE is cleary more relevant with respect to both LDAS-Monde simulations and SMOSMANIA stations. The dynamic of the deep layer moisture content also appears to be consistent with the LDAS-Monde product for deeper layers. However, the bias on these values strongly rely on the calibration of the new two-layers model. The opportunity of improving the two-layers model calibration is then discussed. Finally, the impact of the soil water content initialisation is shown to be significant mainly during the flood rising, and also to be dependent on the model calibration. In conclusion, the new developments presented for the representation of subsurface flow in the MARINE model appear to enhance the soil moisture simulation during flash floods, with respect to both the LDAS-Monde product and the SMOSMANIA observation network.&lt;/p&gt;

Root length density and soil water distribution in drip-irrigated olive orchards in Argentina under arid conditions

2009 ◽  
Vol 60 (3) ◽  
pp. 280 ◽  
Author(s):  
Peter S. Searles ◽  
Diego A. Saravia ◽  
M. Cecilia Rousseaux
Keyword(s):  
Water Content ◽  
Root System ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Length ◽  
Root Length Density ◽  
Soil Depth ◽  
Drip Line ◽  
North West ◽  
Intensively Managed

Several studies have evaluated many above-ground aspects of olive production, but essential root system characteristics have been little examined. The objective of our study was to evaluate root length density (RLD) and root distribution relative to soil water content in three commercial orchards (north-west Argentina). Depending on the orchard, the different drip emitter arrangements included either: (1) emitters spaced continuously at 1-m intervals along the drip line (CE-4; 4 emitters per tree); (2) 4 emitters per tree spaced at 1-m intervals, but with a space of 2 m between emitters of neighbouring trees (E-4); or (3) 2 emitters per tree with 4 m between emitters of neighbouring trees (E-2). All of the orchards included either var. Manzanilla fina or Manzanilla reina trees (5–8 years old) growing in sandy soils, although the specific characteristics of each orchard differed. Root length density values (2.5–3.5 cm/cm3) in the upper soil depth (0–0.5 m) were fairly uniform along the drip line in the continuous emitter (CE-4) orchard. In contrast, roots were more concentrated in the E-4 and E-2 orchards, in some cases with maximum RLD values of up to 7 cm/cm3. Approximately 70% of the root system was located in the upper 0.5 m of soil depth, and most of the roots were within 0.5 m of the drip line. For each of the three orchards, significant linear relationships between soil water content and RLD were detected based on 42 sampling positions that included various distances from the trunk and soil depths. Values of RLD averaged over the entire rooting zone and total tree root length per leaf area for the three orchards were estimated to range from 0.19 to 0.48 cm/cm3 and from 1.8 to 3.5 km/m2, respectively. These results should reduce the uncertainty associated with the magnitude of RLD values under drip irrigation as intensively managed olive orchards continue to expand in established and new growing regions.

Laboratory and field evaluation of five soil water sensors

2004 ◽  
Vol 84 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Q. Huang ◽  
O. O. Akinremi ◽  
R. Sri Rajan ◽  
P. Bullock
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Field Evaluation ◽  
Soil Bulk Density ◽  
Laboratory Evaluation ◽  
Engineering Sciences ◽  
Probe Calibration

Accurate in situ determination of soil water content is important in many fields of agricultural, environmental, hydrological, and engineering sciences. As numerous soil water content sensors are available on the market today, the knowledge of their performance will aid users in the selection of appropriate sensors. The objectives of this study were to evaluate five soil water sensors in the laboratory and to determine if laboratory calibration is appropriate for the field. In this study, the performances of five sensors, including the Profile Probe™ (PP), ThetaProbe™ , Watermark™, Aqua-Tel™, and Aquaterr™ were compared in the laboratory. The PP and ThetaProbe™ were more accurate than the other soil water sensors, reproducing soil water content using factory recommended parameters. However, when PP was installed on a loamy sand in the field, the same soil that was used for the laboratory evaluation, it overestimated field soil water, especially at depth. Another laboratory experiment showed that soil water content readings from the PP were strongly influenced by soil bulk density. The higher the soil bulk density, the greater was the overestimation of soil water content. Two regression parameters, a0 and a1, which are used to convert the apparent dielectric constant to volumetric water content, were found to increase linearly with the soil bulk density in the range of 1.2 to 1.6 Mg m-3. Finally, the PP was calibrated in the field and a good calibration function was obtained with an r2 of 0.87 and RMSE of 2.7%. The values of a0 and a1 obtained in the field were different from factory recommended parameters (a0 = 2.4 versus 1.6 while a1 = 12.5 versus 8.4) and were independent of soil depth, bulk density, and texture. As such, individual field calibration will be necessary to obtain precise and accurate measurement of soil water content with this instrument. Key words: Soil water content, Profile Probe, calibration, soil water content sensor

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